OK, but nothing wrong with a argument now and then
I still think a 30 would be to big for a 5g if its say a Betta tank. If its for fish that can handle current the by all means get the biggest one you can.
8g Fluval 1M CT Betta
125g 5 Blood parrots, 1 Green Severum, 8 Dension Barbs, 10 Yoyo Loaches, 1 RTS
75g Angelfish, 3 EBGR, 4 Siames Alage Eaters, 12 Harlequin Rasboars, 1 BN Pleco, 1 Swordtail
33g long cherry shrimp, 8 pygmy corys, 5 ottos
15g 2 GBR